Pretreatment methods for quantitatively analyzing a sugar chain (Patent Document 1; Non-Patent Document 1). There has been reported a method of detecting a sugar chain rapidly with high sensitivity in order to rapidly analyze the sugar chain, by selectively capturing only a sugar chain released from a glycoprotein, immobilizing the sugar chain on beads, and washing the bead (Non-Patent Document 2). However, an apparatus or pretreatment apparatus that automatically performs a sugar chain analysis using a large amount of a sample such as a blood serum sample, is not known yet.
In the conventional art, purification of a sugar chain contained in a biologically derived mixture of a body fluid such as blood (serum) and a cell/tissue extract, is carried out according to the following steps.
A. A glycoprotein in a sample is reductively alkylated in the presence of a soluble product.
B. A proteolytic enzyme is added thereto to digest the protein moiety with the enzyme, and then the system is heated to deactivate the enzyme.
C. An enzymatic treatment or a chemical treatment which releases a sugar chain from a peptide is carried out to release the sugar chain.
D. Polymer beads displaying a functional group capable of capturing a sugar chain are contacted with a sample which has been finished with the treatment of item C., and thereby the released sugar chain is captured by the functional group of polymer beads.
E. The sample is washed and filtered to remove those impurities that are not captured by the functional group of the polymer beads.
F. The carboxylic acid of a sialic acid residue of the sugar chain captured by the functional group of the polymer beads, is protected by methyl esterifying the functional group.
G. The sugar chain captured by the functional group of the polymer beads is subjected to a reduction of the hydrazone bond to stabilize the binding thereof with the polymer beads.
H. The sugar chain is released from the polymer beads through a hydrazone-oxime exchange reaction, by cleaving the disulfide bond included in sugar chain capturing molecules on beads, or by dispensing an aminooxy-containing compound. In the case of the latter, the treatment of item G. is not carried out.
I. The released sugar chain is recovered in a filtrate.
J. A MALDI matrix is added to the sugar chain-containing filtrate, and then the mixture is added dropwise on a MALDI plate.    Patent Document 1: WO 2004/058687    Non-patent Literature 1: Mol. Cell. Proteomics. 2007; 6:1437-45. Quantitative glycomics of human whole serum glycoproteins based on the standardized protocol for liberating N-glycans. Kita Y, Miura Y, Furukawa J, Nakano M, Shinohara Y, Ohno M, Takimoto A, Nishimura S.    Non-patent Literature 2: Chem. Euro. J. 2007; 13:4797-804. Rapid and simple solid-phase esterification of sialic acid residues for quantitative glycomics by mass spectrometry. Miura Y, Shinohara Y, Furukawa J. Nagahori N, Nishimura S.